1. Field of the Invention
This invention relates to a flame resistant thermoplastic acrylic composition comprising an acrylic polymer matrix, filler and a combination of flame retardant materials. The material is in thin solid surface form which when subjected to a flame is self-extinguishing and generates a minimum amount of smoke.
2. Description of the Prior Art
In developing flame retardant polymeric compositions it is known, as disclosed in U.S. Pat. No. 4,243,579, to use combinations of halogen-containing compounds and antimony oxide to impart flame retardant properties. However, there are several disadvantages in the use of such combinations, which include dense smoke production on burning, and the existence of afterglow on burning. ASTM E-84 specifies a standard test method for surface burning characteristics of building materials. The test results cover two parameters; flame spread and smoke developed during a 10-minute fire exposure. Inorganic cement board and red oak flooring are used as comparative standards and their responses are assigned arbitrary values of 0 and 100 respectively. The classifications are as follows for interior wall and ceilings.
ASTME E-84 TEST CLASSIFICATIONS Class Flame Spread Smoke Developed I 0-25 0-450 II 26-75 0-450 III 76-200 0-450
While thick sheets of known solid surface materials may meet Class I standards, sheets having a thickness of less than about 0.25 inch (0.635 cm) have not met the Class I standard. Accordingly, there is a need to provide new compositions, which meet the ASTM E-84 Class I test.